Used primarily in bioconjugation chemistry, this reagent enables the selective attachment of functional groups to thiol-containing molecules due to its bromoacetate moiety, which reacts efficiently with cysteine residues in peptides and proteins. The N-hydroxysuccinimide ester group allows for simultaneous or sequential conjugation to amine groups, making it valuable for crosslinking biomolecules in immunoassays and protein labeling. It is also employed in the synthesis of antibody-drug conjugates and in modifying surfaces of biosensors where controlled immobilization of biomolecules is required. Its dual reactivity supports the development of complex molecular architectures in pharmaceutical research and diagnostic applications.